Cell c has destroyed my life

It took me over a week to decide whether should i share my disgusted experience with this cell c company, or should I just move on with my life. But unfortunately I can't move on with my life as cell c has destroyed it, after 21 months I have been paying cell c without any issues, however the first week of September I made an arrangement with cell c to move my debit dates from debiting on 26 of every month to the 1 of the month since I'm self employed. I also queried the over billing I was told that I subscribed to some things which I was not aware of, then I cancelled all those subscriptions. After my humble request to debit on the first of every month it was ignored and they debited on the 26 of September and there's was not enough money as the money I reserved was for small amount like legal wise, old mutual, clientele and other small amounts, this negligence by cell c really affected my life so badly as my bank statement had too many returned deposit and I was charged over R700 for unpaid. I called cell c on the 21 and 22 of October 2018 cancelling my contract as it's due on the 23 of November, I was told that I'm owing money, when I queried about my arrangement that I arranged with cell c, they put me through to all different people and I did not get any help. In October they did the same thing debiting on the 26 and also on the first of November. I went to buy my business car and I was declined because of what cell c has done to me. My bank statement had too many deposit and I just wonder if anyone from cell c will take my complain seriously. I will hear from you.